Bug 2049691

Summary:	Malformed DHCPv6 NTP option
Product:	Red Hat Enterprise Linux 8	Reporter:	Miroslav Lichvar <mlichvar>
Component:	dnsmasq	Assignee:	Petr Menšík <pemensik>
Status:	CLOSED ERRATA	QA Contact:	Petr Sklenar <psklenar>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	8.5	CC:	psklenar
Target Milestone:	rc	Keywords:	Patch, Triaged
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	dnsmasq-2.79-23.el8	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-11-08 10:01:07 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Deadline:	2022-04-04

Description Miroslav Lichvar 2022-02-02 14:49:34 UTC

Description of problem:
dnsmasq as a DHCPv6 server doesn't correctly form the NTP server option (56) in its responses. It doesn't use the suboptions specified in RFC 5908.

This was fixed in upstream commit dded78b2338147daf69064d6d48c16b12744e441.


Version-Release number of selected component (if applicable):
dnsmasq-2.79-19.el8.x86_64

How reproducible:
always

Steps to Reproduce:
1. add "dhcp-option=option6:ntp-server,[2001:db8:ca2:2::1]" to configuration
2. restart dnsmasq
3. start tshark -V -f 'port 547'
4. wait for DHCP response

Actual results:
Malformed message

Expected results:
NTP server option contains NTP server address suboption

Additional info:

Comment 1 Petr Menšík 2022-03-11 12:03:15 UTC

Seems reasonable. While it were possible to encode correct payload in hex format, that is unconvenient and inpractical. It is just small addition and self contained. Already present in RHEL9.

Upstream commit: http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=dded78b2338147daf69064d6d48c16b12744e441

Comment 17 errata-xmlrpc 2022-11-08 10:01:07 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: dnsmasq security and bug fix update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2022:7633